Indexing rotary actuator with energy storage and linkage locking means

Abstract

An indexing rotary actuator for applying the torque of a rotatable pivot arm to rotate a member between plural index positions. The forward stroke of the pivot arm drives a slider crank linkage through a four bar linkage to unlock the rotatable member and rotate the member to its next index position. On the return stroke of the pivot arm a spring biased locking arm on the rotatable member is interlocked with the actuator to lock the rotatable member in the index position. Interlock switches are provided to indicate when a rotated member is in a valid index position.

What is claimed is: 
     
       1. An indexing rotary actuator for unlocking a rotatable member, rotating the rotatable member to an index position and locking said rotatable member in said index position, said indexing rotary actuator comprising: an actuatable pivot arm;   unlocking means responsive to the actuation of said pivot arm for unlocking said rotatable member;   means for rotating said rotatable member to an index position;   locking means responsive to the release of said pivot arm for locking said rotatable member in said index position;   at least one locking arm, cooperating with said locking means and said unlocking means, for locking and unlocking said rotatable member in an index position;   a guide block;   a locking arm receiving aperture in said guide block;   an upper guide surface on said guide block for guiding a locking arm into said aperture;   a lower guiding surface on said guide block for guiding a locking arm away from said aperture; and   a channel through said guide block communicating with said aperture adapted to receive an unlatching pin.   
     
     
       2. The indexing rotary actuator of claim 1 wherein said unlocking means comprises: a rotatable pivot shaft rotated by the actuation of said pivot arm;   unlatching pin means received in said channel and adapted to unlock said rotatable member by displacing a locking arm received in said aperture; and   linkage means interconnecting said pivot shaft and said unlatching pin means for extending said unlatching pin means within said channel into said aperture to displace a locking arm received in said aperture and for retracting said unlatching pin means from said aperture.   
     
     
       3. The indexing rotary actuator of claim 2 wherein said means for rotating said rotatable member comprises: a rotatable main shaft for rotatably mounting said rotatable member;   a main shaft pulley mounted on said rotatable main shaft for rotation therewith;   a pivot shaft pulley mounted on said pivot shaft for rotation therewith;   a rotatable transmission pulley;   linkage means connecting said pivot arm with said transmission pulley to partially rotate said transmission pulley upon actuation of said pivot arm;   a flexible belt circumscribing said transmission pulley, said main shaft pulley and said pivot shaft pulley, said flexible belt storing energy in the form of axial stress during the actuation of said pivot member and releasing said axial stress to rotate said rotatable main shaft upon the unlocking of said rotatable member by said unlocking means; and   spring means for biasing said pivot shaft into a non-actuated position when said pivot arm is not actuated.   
     
     
       4. The indexing rotary actuator of claim 3 wherein said locking means comprises: locking arm spring means for biasing said locking arm into contact with said upper guide surface such that said locking arm travels along said upper guide surface toward said aperture upon rotation of said rotatable member toward an index position;   unlatching pin biasing means for retracting said unlatching arm in said channel to permit said aperture to receive a locking arm; and   means for biasing said pivot arm into a non-actuated position.   
     
     
       5. The indexing rotary actuator of claim 4 further including means for generating an interlock signal when said rotatable member is in an index position, said means comprising an interlock switch and means mounted on said rotatable member for actuating said switch when said rotatable member is in an index position. 
     
     
       6. The indexing rotary actuator of claim 2 wherein said linkage means comprises a four bar linkage coupled to a slider crank linkage, said four bar linkage also being coupled to said pivot shaft and said slider crank linkage also being coupled to said unlatching pin means. 
     
     
       7. The indexing rotary actuator of claim 3 further including stop means for preventing the rotation of said rotatable member past an index position. 
     
     
       8. An indexing rotary actuator for rotating a rotatable member into index positions wherein the forward stroke of a pivot arm provides torque for unlocking the rotatable member and rotating the rotatable member into an index position and the return stroke of the pivot arm results in locking the rotatable member in said index position, said actuator comprising: at least one displaceable locking arm on said rotatable member;   means cooperating with said locking arm to lock said rotatable member in an index position;   actuatable unlocking means cooperating with said last mentioned means and said locking arm for unlocking said rotatable member;   linkage means for actuating said unlocking means during the forward stroke of said pivot arm to unlock said rotatable member;   rotation means coupled to said pivot arm and said rotatable member for rotating said rotatable member to an index position during the forward stroke of said pivot arm after said rotatable member has been unlocked; and   means responsive to the return stroke of the pivot arm means for locking said rotatable member in said index position.